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/*Copyright (c) 2011, Florent DEVILLE.                                      */
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#include "RTPointLight.h"

namespace RT
{
	/*Constructor*/
	RTPointLight::RTPointLight(const RTVector3f& center, const RTColor& color, const RTVector3f& attenuation):
			m_center(center), m_color(color), m_attenuation(attenuation)
	{
		m_type = ePoI32Light;	
	}

	/*Destructor*/
	RTPointLight::~RTPointLight(){}

	/*Calculate the color of the light*/
	RTColor RTPointLight::computeColor(const RTRay& /*ray*/, F32 dist)const
	{
		//if no attenuation
		if(m_attenuation.norme2() == 0)
			return m_color;
		else//calculate attenuation
			return m_color / (m_attenuation.x + m_attenuation.y * dist + m_attenuation.z * dist * dist);
	}

	/*Calculate the shadow ray between a point and the light*/
	void RTPointLight::computeShadowRay(const RTVector3f& point, RTRay& shadowRay, F32* distance)const
	{
		//get a ray from the object to the light
		RTVector3f L = m_viewCenter - point;
		*distance = L.norme();
		L.normalize();

		//to avoid intersection with itslef
		shadowRay.setOrigin(point + (L * 0.01f));
		shadowRay.setDirection(L);
	}

	/*Apply the view matrix to the light*/
	void RTPointLight::applyViewMatrix(const RTMatrix44& view)
	{
		//m_center = m_center * view;
		m_viewCenter = m_center * view;
	}

	/*Set the light position*/
	void RTPointLight::setPosition(const RTVector3f& position)
	{
		m_center = position;
	}

}